1. Field of the Invention
THIS INVENTION relates to a snow making method and apparatus.
The invention particularly relates, but is not limited to, an improved snow making method, and apparatus therefor, for making man-made snow and ice crystals, to be used for covering skiing slopes with man-made snow; for Indoor ski centres; and for the commercial issue of ice or domestic or cooling requirements.
2. Prior Art
U.S. Pat. No. 5,297,731 (Aiflo Bucceri) disclosed a snow making technique and apparatus where ice crystals were formed within multiple hoses and were dislodged by passing a roller mechanism over the hoses. The machinery was limited to a particular area of snow production only, being bulky and difficult to move around the field. As well, the machine could not be easily used on an unprepared or rough ground. The coolant requirement was high, and one leak could lead to a costly replacement. The machines could not be economically produced in bulk supply, due to the many man hours required to produce the machine. The method of dislodging the ice crystals could cause machinery downtime, due to the fact that one roller mechanism was working on multiple hoses. Therefore, if one hose failed, all the other hoses were non-productive while repairs were effected. In addition, the end product was sometimes too wet for immediate use and required further drainage, and the hoses were limited to short lengths due to the complexity of the machinery.
International Patent Application PCT/AU99/00312 (International Publication No WO 99/56067) (Alfio Bucceri) disclosed a snow making machine having at least one flexible hose assembly, with an inner hose connected to a water supply and an outer jacket to receive coolant from a chiller. Ice/snow formed in the inner hose was dislodged by inflating squasher hoses in the outer jacket, and pressurized air fed via a line to the inner hose could assist transport of the dry snow crystals to the end of the hose assembly. In one embodiment, the hose assemblies are deformed using a pair of rollers which travel in concert along rails to release the ice formed on the walls of the inner hoses.
The disadvantages of the method and apparatus of PCT/AU99/00312 included the necessity to have up to three hoses within the outer jacket, ie., the inner hose, the squasher hose, and the pressurized air hose; and that the wall thicknesses of both the inner hoses and outer jackets must be relatively thick to withstand the deformation by the roller assemblies —the thickness of the inner hoses, in particular, reducing the rate of heat transfer from the coolant in the outer jackets to the water in the inner hoses.